from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The large rounded structure of the brain occupying most of the cranial cavity, divided into two cerebral hemispheres that are joined at the bottom by the corpus callosum. It controls and integrates motor, sensory, and higher mental functions, such as thought, reason, emotion, and memory.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The upper part of the brain, which is divided into the two cerebral hemispheres. In humans it is the largest part of the brain and is the seat of motor and sensory functions, and the higher mental functions such as consciousness, thought, reason, emotion, and memory.

from the GNU version of the Collaborative International Dictionary of English

  • n. The anterior, and in man the larger, division of the brain; the seat of the reasoning faculties and the will. See brain.

from The Century Dictionary and Cyclopedia

  • n. The entire brain; the encephalon.
  • n. That portion of the brain which lies in front of the cerebellum and pons Varolii.
  • n. The two cerebral hemispheres taken together, with the olfactory lobes; the prosencephalon. See cerebral hemisphere, under cerebral.
  • n. In insects, the supra-esophageal ganglion, formed by the union of several ganglia in the upper part of the head, and often called the brain.
  • n. In invertebrates generally, the principal nervous ganglion or ganglia of the head.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. anterior portion of the brain consisting of two hemispheres; dominant part of the brain in humans


Latin, brain; see ker-1 in Indo-European roots.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin cerebrum ("brain, skull"), from Proto-Indo-European *ḱara-, *ḱeras-, *ḱrās- (“head”). Cognate with Ancient Greek κάρα (kára, "head"), Old High German hirni ("brain"), Old English hærn ("brain"). More at harns. (Wiktionary)



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